Unidentified gunmen have shot and killed a senior advisor to Palestinian leader Yasser Arafat in Gaza. No one has claimed responsibility for the attack, and no suspects have been arrested. Khalil al-Zaben was leaving his office in Gaza City in the early morning hours when he was gunned down.

Yasser Arafat called the murder of his long-time advisor a dirty assassination and convened an urgent meeting of the Palestinian leadership to discuss the issue.

Mr. al-Zaben was well known as an Arafat loyalist. He was also a publisher and headed a human rights group funded by the Palestinian Authority. He had recently condemned the actions of rival militia gangs as the work of professional killers and assassins.

Some Palestinian officials have said those comments would certainly have made him enemies.

His murder is seen as a direct challenge to Mr. Arafat's authority and has renewed concern about growing lawlessness and political infighting in the Palestinian areas.

There have been numerous reports of armed men forcing their way into offices and of gun battles between rival militia gangs.

In one incident recently, rival groups engaged in a shootout at the Gaza police headquarters. Then, last week, armed men briefly occupied the offices of the Palestinian Broadcasting Corporation in Gaza. Palestinian journalists have called for the authorities to investigate recent attacks against them as well.

Analysts find the incidents troubling because there are several groups involved in these incidents.

Palestinian sociologist Nader Sayid of Birzeit University in Ramallah, says the recent attacks are signs of a society that has lost confidence in its institutions.

Professor Sayid blames more than three years of Israeli-Palestinian violence and the resulting rise in unemployment and poverty.

"There is the part which has to do with the suffering Palestinians are facing and the loss of hope for the future, and the loss of direction, especially among the youth who are unable to see where is this society going and what are the common values and what are the common objectives," he said.

He added that more attention must be paid to social problems and issues or there will be more violence and chaos.

There are growing fears that if the Israelis implement Prime Minister Ariel Sharon's plan and pull out of Gaza, the resulting power vacuum could plunge the area into even greater turmoil.